1. Field of the Invention
This invention generally relates to a bicycle crank assembly that includes one or more bicycle sprockets.
2. Background Information
Most bicycles have a drive unit or drive train that uses a chain to transmit the pedaling action from the rider to the rear wheel. A bicycle drive train typically has one or more front sprockets provided on a bicycle crank assembly of the bicycle and one or more rear sprockets provided on a rear hub of the bicycle. The chain wraps around the front and rear sprockets. Thus, rotation of the bicycle crank assembly by the rider is transmitted to the rear wheel by the chain, which meshes with the front and rear sprockets. A bicycle chain has a plurality of inner links and a plurality of outer links that are interconnected in an alternating manner by a plurality of pins. Typically, each of the inner links includes a pair of parallel inner link plates connected by the pins that are surrounded by cylindrical rollers. Each of the outer links includes a pair of parallel outer link plates connected by the pins of the adjacent inner links. In this way, the inner links and the outer links are linked alternately. Therefore, when the teeth of a sprocket all have the same thickness, gaps occur between the outer link plates and the teeth of the sprocket that are larger than the gaps between the inner link plates and the teeth of the sprocket. In view of this situation, sprockets have been proposed in which the axial widths of the teeth meshing with the outer links are greater than the axial widths of the teeth meshing with the inner links (see, for example U.S. Pat. No. 4,174,642).